<template>
    <view class="uni-combox" :class="border ? '' : 'uni-combox__no-border'">
        <view v-if="label" class="uni-combox__label" :style="labelStyle">
            <text>{{label}}</text>
        </view>
        <view class="uni-combox__input-box">
            <input class="uni-combox__input" type="text" :placeholder="placeholder"
                   placeholder-class="uni-combox__input-plac" v-model="inputVal" @input="onInput" @focus="onFocus"
                   @blur="onBlur"/>
            <uni-icons :type="showSelector? 'top' : 'bottom'" size="14" color="#999" @click="toggleSelector">
            </uni-icons>
        </view>
        <view class="uni-combox__selector" v-if="showSelector">
            <view class="uni-popper__arrow"></view>
            <scroll-view scroll-y="true" class="uni-combox__selector-scroll">
                <view class="uni-combox__selector-empty" v-if="filterCandidatesLength === 0">
                    <text>{{emptyTips}}</text>
                </view>
                <view class="uni-combox__selector-item" v-for="(item,index) in filterCandidates" :key="index"
                      @click="onSelectorClick(index)">
                    <text>{{item}}</text>
                </view>
            </scroll-view>
        </view>
    </view>
</template>

<script>
    /**
     * Combox 组合输入框
     * @description 组合输入框一般用于既可以输入也可以选择的场景
     * @tutorial https://ext.dcloud.net.cn/plugin?id=1261
     * @property {String} label 左侧文字
     * @property {String} labelWidth 左侧内容宽度
     * @property {String} placeholder 输入框占位符
     * @property {Array} candidates 候选项列表
     * @property {String} emptyTips 筛选结果为空时显示的文字
     * @property {String} value 组合框的值
     */
    export default {
        name: 'uniCombox',
        emits: ['input', 'update:modelValue'],
        props: {
            border: {
                type: Boolean,
                default: true
            },
            label: {
                type: String,
                default: ''
            },
            labelWidth: {
                type: String,
                default: 'auto'
            },
            placeholder: {
                type: String,
                default: ''
            },
            candidates: {
                type: Array,
                default() {
                    return []
                }
            },
            emptyTips: {
                type: String,
                default: '无匹配项'
            },
            // #ifndef VUE3
            value: {
                type: [String, Number],
                default: ''
            },
            // #endif
            // #ifdef VUE3
            modelValue: {
                type: [String, Number],
                default: ''
            },
            // #endif
        },
        data() {
            return {
                showSelector: false,
                inputVal: ''
            }
        },
        computed: {
            labelStyle() {
                if (this.labelWidth === 'auto') {
                    return ""
                }
                return `width: ${this.labelWidth}`
            },
            filterCandidates() {
                return this.candidates.filter((item) => {
                    return item.toString().indexOf(this.inputVal) > -1
                })
            },
            filterCandidatesLength() {
                return this.filterCandidates.length
            }
        },
        watch: {
            // #ifndef VUE3
            value: {
                handler(newVal) {
                    this.inputVal = newVal
                },
                immediate: true
            },
            // #endif
            // #ifdef VUE3
            modelValue: {
                handler(newVal) {
                    this.inputVal = newVal
                },
                immediate: true
            },
            // #endif
        },
        methods: {
            toggleSelector() {
                this.showSelector = !this.showSelector
            },
            onFocus() {
                this.showSelector = true
            },
            onBlur() {
                setTimeout(() => {
                    this.showSelector = false
                }, 153)
            },
            onSelectorClick(index) {
                this.inputVal = this.filterCandidates[index]
                this.showSelector = false
                this.$emit('input', this.inputVal)
                this.$emit('update:modelValue', this.inputVal)
            },
            onInput() {
                setTimeout(() => {
                    this.$emit('input', this.inputVal)
                    this.$emit('update:modelValue', this.inputVal)
                })
            }
        }
    }
</script>

<style lang="scss">
    .uni-combox {
        font-size: 14px;
        border: 1px solid #DCDFE6;
        border-radius: 4px;
        padding: 6px 10px;
        position: relative;
        /* #ifndef APP-NVUE */
        display: flex;
        /* #endif */
        // height: 40px;
        flex-direction: row;
        align-items: center;
        // border-bottom: solid 1px #DDDDDD;
    }

    .uni-combox__label {
        font-size: 16px;
        line-height: 22px;
        padding-right: 10px;
        color: #999999;
    }

    .uni-combox__input-box {
        position: relative;
        /* #ifndef APP-NVUE */
        display: flex;
        /* #endif */
        flex: 1;
        flex-direction: row;
        align-items: center;
    }

    .uni-combox__input {
        flex: 1;
        font-size: 14px;
        height: 22px;
        line-height: 22px;
    }

    .uni-combox__input-plac {
        font-size: 14px;
        color: #999;
    }

    .uni-combox__selector {
        /* #ifndef APP-NVUE */
        box-sizing: border-box;
        /* #endif */
        position: absolute;
        top: calc(100% + 12px);
        left: 0;
        width: 100%;
        background-color: #FFFFFF;
        border: 1px solid #EBEEF5;
        border-radius: 6px;
        box-shadow: 0 2px 12px 0 rgba(0, 0, 0, 0.1);
        z-index: 2;
        padding: 4px 0;
    }

    .uni-combox__selector-scroll {
        /* #ifndef APP-NVUE */
        max-height: 200px;
        box-sizing: border-box;
        /* #endif */
    }

    .uni-combox__selector-empty,
    .uni-combox__selector-item {
        /* #ifndef APP-NVUE */
        display: flex;
        cursor: pointer;
        /* #endif */
        line-height: 36px;
        font-size: 14px;
        text-align: center;
        // border-bottom: solid 1px #DDDDDD;
        padding: 0px 10px;
    }

    .uni-combox__selector-item:hover {
        background-color: #f9f9f9;
    }

    .uni-combox__selector-empty:last-child,
    .uni-combox__selector-item:last-child {
        /* #ifndef APP-NVUE */
        border-bottom: none;
        /* #endif */
    }

    // picker 弹出层通用的指示小三角
    .uni-popper__arrow,
    .uni-popper__arrow::after {
        position: absolute;
        display: block;
        width: 0;
        height: 0;
        border-color: transparent;
        border-style: solid;
        border-width: 6px;
    }

    .uni-popper__arrow {
        filter: drop-shadow(0 2px 12px rgba(0, 0, 0, 0.03));
        top: -6px;
        left: 10%;
        margin-right: 3px;
        border-top-width: 0;
        border-bottom-color: #EBEEF5;
    }

    .uni-popper__arrow::after {
        content: " ";
        top: 1px;
        margin-left: -6px;
        border-top-width: 0;
        border-bottom-color: #fff;
    }

    .uni-combox__no-border {
        border: none;
    }
</style>
